Another View of Google's Dominance
(eMarketer)

Looks like DoubleClick was a very savvy buy.

Online ad networks offer site publishers a big revenue opportunity, according to a January 2008 study conducted jointly by Attributor and Compete.

The companies looked at content monetization and user information across 68 million domains. DoubleClick and Google dominated overall market share capturing 35% and 34% of unique users, respectively.

"DoubleClick owns the head and Google owns the tail," said Attributor on its blog.

The company noted that Doubleclick had nearly half of the total market for ads on sites with more than a million monthly unique users. Google had more than 70% of the market for sites with less than 100,000 monthly unique users.